The extraordinary, but previously hidden, story of a British engineer, Tommy Flowers, and a talented British mathematician, Bill Tutte. Tutte's codebreaking skill, and the engineering genius of Flowers, gave rise to Colossus, the world's first programmable computer. Tutte is revealed as having been responsible for what experts have described as the single most important intellectual feat of World War Two - without this work, D Day would never have happened. Tutte broke a code ten times tougher than Enigma and, with a handful of brilliant men, allowed Churchill to 'hack in' to Hitler's own hotline, win the War and usher in the age of computers. Tutte's breathtaking genius was exploited by an amazing array of talent at Bletchley Park (the UK's top secret intelligence base) who then broke into Hitler's own communications network, changing the War and the world. Using dramatic reconstructions to recreate the daring raid, Codebreakers: Bletchley Park's Lost Heroes brings to life a mission that would come to symbolize the fighting spirit of the British, and throws new light on the institutional rivalry that would ultimately lead the country from its darkest hours to victory.